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use core::ptr;
use crate::hal::spi::{FullDuplex, Mode, Phase, Polarity};
use nb;
use crate::stm32::{SPI1, SPI3};
use crate::gpio::gpioa::{PA5, PA6, PA7};
use crate::gpio::{AF5, Input, Floating, Alternate};
use crate::rcc::{APB1R1, APB2, Clocks};
use crate::time::Hertz;
#[derive(Debug)]
pub enum Error {
Overrun,
ModeFault,
Crc,
#[doc(hidden)]
_Extensible,
}
pub trait Pins<SPI> {
const REMAP: bool;
}
impl Pins<SPI1>
for (
PA5<Alternate<AF5, Input<Floating>>>,
PA6<Alternate<AF5, Input<Floating>>>,
PA7<Alternate<AF5, Input<Floating>>>,
)
{
const REMAP: bool = false;
}
pub struct Spi<SPI, PINS> {
spi: SPI,
pins: PINS,
}
macro_rules! hal {
($($SPIX:ident: ($spiX:ident, $APBX:ident, $spiXen:ident, $spiXrst:ident, $pclkX:ident),)+) => {
$(
impl<PINS> Spi<$SPIX, PINS> {
pub fn $spiX<F>(
spi: $SPIX,
pins: PINS,
mode: Mode,
freq: F,
clocks: Clocks,
apb2: &mut $APBX,
) -> Self
where
F: Into<Hertz>,
PINS: Pins<$SPIX>
{
apb2.enr().modify(|_, w| w.$spiXen().set_bit());
apb2.rstr().modify(|_, w| w.$spiXrst().set_bit());
apb2.rstr().modify(|_, w| w.$spiXrst().clear_bit());
spi.cr2
.write(|w| unsafe {
w.frxth().set_bit().ds().bits(0b111).ssoe().clear_bit()
});
let br = match clocks.$pclkX().0 / freq.into().0 {
0 => unreachable!(),
1...2 => 0b000,
3...5 => 0b001,
6...11 => 0b010,
12...23 => 0b011,
24...39 => 0b100,
40...95 => 0b101,
96...191 => 0b110,
_ => 0b111,
};
spi.cr1.write(|w| unsafe {
w.cpha()
.bit(mode.phase == Phase::CaptureOnSecondTransition)
.cpol()
.bit(mode.polarity == Polarity::IdleHigh)
.mstr()
.set_bit()
.br()
.bits(br)
.spe()
.set_bit()
.lsbfirst()
.clear_bit()
.ssi()
.set_bit()
.ssm()
.set_bit()
.crcen()
.clear_bit()
.bidimode()
.clear_bit()
});
Spi { spi, pins }
}
pub fn free(self) -> ($SPIX, PINS) {
(self.spi, self.pins)
}
}
impl<PINS> FullDuplex<u8> for Spi<$SPIX, PINS> {
type Error = Error;
fn read(&mut self) -> nb::Result<u8, Error> {
let sr = self.spi.sr.read();
Err(if sr.ovr().bit_is_set() {
nb::Error::Other(Error::Overrun)
} else if sr.modf().bit_is_set() {
nb::Error::Other(Error::ModeFault)
} else if sr.crcerr().bit_is_set() {
nb::Error::Other(Error::Crc)
} else if sr.rxne().bit_is_set() {
return Ok(unsafe {
ptr::read_volatile(&self.spi.dr as *const _ as *const u8)
});
} else {
nb::Error::WouldBlock
})
}
fn send(&mut self, byte: u8) -> nb::Result<(), Error> {
let sr = self.spi.sr.read();
Err(if sr.ovr().bit_is_set() {
nb::Error::Other(Error::Overrun)
} else if sr.modf().bit_is_set() {
nb::Error::Other(Error::ModeFault)
} else if sr.crcerr().bit_is_set() {
nb::Error::Other(Error::Crc)
} else if sr.txe().bit_is_set() {
unsafe { ptr::write_volatile(&self.spi.dr as *const _ as *mut u8, byte) }
return Ok(());
} else {
nb::Error::WouldBlock
})
}
}
impl<PINS> crate::hal::blocking::spi::transfer::Default<u8> for Spi<$SPIX, PINS> {}
impl<PINS> crate::hal::blocking::spi::write::Default<u8> for Spi<$SPIX, PINS> {}
)+
}
}
hal! {
SPI1: (spi1, APB2, spi1en, spi1rst, pclk2),
SPI3: (spi3, APB1R1, spi3en, spi3rst, pclk1),
}